Mobile suspension systems for such a purpose are known in which a supporting apparatus runs along an overhead track and a simple example is disclosed in U.S. Pat. No. 3,006,481 issued Oct. 31, 1961 in the name of Nathan A. Gussack. Since such a device will move along the track when touched or when the track is slightly sloped, it is advantageous to be able to lock the device in one position on the track when it is in use. A supporting apparatus having a locking device is disclosed in U.S. Pat. No. 3,321,090 issued May 23, 1967 in the name of J. C. Greenstad. The Greenstadt device has the advantage that it locks in place on the track when a weight is suspended from it but it has a number of working parts which makes it relatively complex in construction and expensive to manufacture and susceptible to breakdown.
It is an object of the present invention to provide an improved hanger which is of simplified construction and more reliable in operation.